Method of fabricating a knife handle

ABSTRACT

In the fabrication of knife handles having a plastic cover attached to a metal liner, the covers are molded with at least two studs projecting from the side of the cover which faces the metal liner. Holes are provided in the liner through which the studs are inserted with opposing faces of the cover and liner flush. An annular depression is formed in the cover around each stud to accommodate any burrs or protrusions of the metal liner formed while making the holes for the studs.

States Patent 1191 Unite [11} 3,754,319

Miori Aug. 28, 1973 [54] METHOD OF FABRICATING A KNIFE 3,001,279 9/1961Sherrill 1. 29/509 UX R HANDLE 3,308,225 3/1967 Wells 264/249 3,463,61112/1969 Balamuth et al 29/509 [75] Inventor: Nilo M. Miori, Solvey, N.Y.

FOREIGN PATENTS OR APPLICATIONS [73] Asmgnee 5:2 cmmy 1,071,535 12/1959Germany 30/340 [22] Filed: Feb. 18, 1972 Primary Examiner-Charlie T.Moon [21] Appl No 227 519 Attorney-Francis P. Keiper et al.

57 ABSTRACT [52] US. Cl 29/509, 29/522, 30/340, 1

264/249 In the fabrication of knife handles having a plastic 511 1111.C1 B211! 39/00, B23p 11/00 much 8 line" are molded [58} Field of Search29/509, 522- 30/340 with at least Studs Pmiecting fwm the side 30/342344, cover which faces the metal liner. Holes are provided in the linerthrough which the studs are inserted with 56] References Cited opposingfaces of the cover and liner flush. An annular depression is formed inthe cover around each stud to UNITED STATES PATENTS accommodate anyburrs or protrusions of the metal gzmzg i l' g liner formed while makingthe holes for the studs. 2,958,230 11/1960 Haroldson 29/509 UX R 5Claims, 3 Drawing Figures METHOD OF FABRICATING A KNIFE HANDLE Thepresent invention relates to the fabrication of knife handles and toimproved construction and methods which involve attaching a plasticknife handle cover to a metal liner.

For many years it has been the practice to make knife handles with anouter covering of a suitable plastic attached to an underlying liner ofmetal. A handle which is attractive, durable and economical, as well aseasily produced in any desired color and design, is thereby provided. Itis necessary, of course, to fabricate the handle in a manner whichinsures a secure and lasting connection between the plastic and metal.

Probably the most common method of attaching covers and liners,particularly in the case of folding blade pocket knives, and the like,is with a number of rivets initially separate from both the cover andliner. While a satisfactory attachment may be provided thereby, the headof the rivet on the cover side must be polished or covered to present asatisfactory appearance. Thus, the cost of this means of attachment ishigher than a satisfactory attachment means which does not employseparate rivets. Other methods have been proposed to attach the coverand liner without the use of separate rivets, such as providing lugs onthe plastic cover which resiliently snap into notches or cut-outs in theliner, but all suffer from some disadvantages.

It is a principal object of the present invention to provide anattractive and economical knife handle construction, as well as a methodof effecting a secure, permanent connection of a plastic knife handlecover to a metal liner which is superior to former methods of performingthe same function.

A further object is to provide a method of attaching a plastic knifehandle cover to a metal liner which involves no separate parts andinsures a flush fit between opposing surfaces of the handle and liner.

The above and other novel features of the invention will appear morefully hereinafter from the following detailed description when taken inconjunction with the accompanying drawings. It is expressly understoodthat the drawings are employed for purposes of illustration only and arenot designed as a definition of the limits of the invention, referencebeing had for this purpose to the appended claims.

In the drawings, wherein like reference characters indicate like parts:

FIG. 1 is a perspective view showing the inner sides ofa knife cover andliner, ready for assembly according to the present invention;

FIG. 2 is an enlarged side elevational view of a portion of the knifecover in section on the line 2-2 of FIG. 1;

FIG. 3 is a side sectional view of the portion of the cover shown inFIG. 2 after attachment to the liner according to the invention.

Referring now to the drawings, knife handle cover I is formed in adesired shape, normally corresponding over at least a major portion ofits periphery to knife handle liner 12. Cover is commonly made bym0lding a suitable plastic, a preferred example for employment in thepresent invention being that sold by Dupont under the trademark Delrin,or other such acetal resin homopolymer. Liner 12 is usually a metalstamping, e.g., brass, flat on both sides. Surface 14 of cover 10 isalso flat, and lies flush with the opposing surface of liner 12 when thehandle is assembled.

Studs 16 are formed integrally with cover 10 and extend outwardly fromsurface 14 with annular depression 18 around the base of each stud. Thestuds are preferable at least two in number and located adjacentopposite ends of the cover. As best seen in FIG. 2, the ends of studs 16are slightly convex, coming to a shallow point at the center. Examplesof suitable values of the dimensions indicated by letter in FIG. 2 for aknife handle of several inches in length are:

A 0125 inches B 0.045 inches C 0.025 inches E 7/32 inches Holes 20 arepunched in metal liner 12, of about the same or very slightly largerdiameter than studs 16, and with the same center-to-center distance. Theheight of studs 16 above surface 14 (i.e. dimension 8) is substantiallyequal to or slightly greater than the thickness of liner 12. Thus, whensurface 14 of the cover and the opposing surface of the liner are placedin contact, with studs 16 extending through holes 20, a small amount ofthe material of the stud extends past the opposite surface of the liner.It is common for a burr, or small amount of protruding material such asthat indicated by reference numeral 22 in FIG. 3, to extend from liner12 around holes 20. Annular depressions I8 insure that the cover andliner will still lie flush since the burr may extend into thedepression, which has a depth great enough to accommodate at least theaverage burrs or projections which may be expected. The end portion ofthe stud is then upset so that the cover and liner are joined, as seenin FIG. 3.

Additional holes 24 are provided in liner 12 for mounting knife bladepivot pins, and the like.

The upsetting is preferably performed by mechanical means such as avibrating hammer. A better and more lasting connection has been achievedin this manner than, for example, by heat smearing the plastic on theopposite side of the liner, although it is sometimes more convenient, asin replacing broken handle covers, to use the heat smear method.

While several forms of the invention have been illustrated anddescribed, it is to be understood that the invention is not limitedthereto. As various changes in the construction and arrangement may bemade without departing from the spirit of the invention, as will beapparent to those skilled in the art, reference will be had to theappended claims for a definition of the limits of the invention.

What is claimed is:

l. A method of fabricating a knife handle having a plastic outer coverand a metal liner, said method comprising:

a. molding the outer cover from a suitable plastic material with atleast one major surface substantially flat, at least two studs moldedintegrally with said cover and extending from said flat major surface,and an annular depression around each of said studs;

b. forming the liner of a flat piece of metal having a desiredperipheral shape, and punched holes extending therethrough ofsubstantially the same diameter and spacing as the studs on the cover,one

3. The invention according to claim 2 wherein said ends of the studs aremechanically upset with a vibrating hammer.

4. The invention according to claim 3 wherein said plastic is an acetalresin homopolymer.

5. The invention according to claim 1 wherein the depth of said annulardepressions is great enough to accommodate average projections or burrson said metal liner around the holes therein, whereby said cover andliner will fit in contacting engagement in spite of such projections orburrs.

1. A method of fabricating a knife handle having a plastic outer coverand a metal liner, said method comprising: a. molding the outer coverfrom a suitable plastic material with at least one major surfacesubstantially flat, at least two studs molded integrally with said coverand extending from said flat major surface, and an annular depressionaround each of said studs; b. forming the liner of a flat piece of metalhaving a desired peripheral shape, and punched holes extendingtherethrough of substantially the same diameter and spacing as the studson the cover, one surface of said liner having projections or burrsaround the holes formed by punching; c. placing said flat major surfaceof the cover in engagement with said one surface of the liner with thestuds extending through the holes; and d. upsetting the ends of thestuds on the opposite side of the liner from the cover, thereby forminghead portions retaining said cover and liner in contacting engagement.2. The invention according to claim 1 wherein said ends of the studs aremechanically upset to form said head portions.
 3. The inventionaccording to claim 2 wherein said ends of the studs are mechanicallyupset with a vibrating hammer.
 4. The invention according to claim 3wherein said plastic is an acetal resin homopolymer.
 5. The inventionaccording to claim 1 wherein the depth of said annular depressions isgreat enough to accommodate average projections or burrs on said metalliner around the holes therein, whereby said cover and liner will fit incontacting engagement in spite of such projections or burrs.